Scientific article
OA Policy
English

Ultrafast broadband circular dichroism in the deep ultraviolet

Published inOptica, vol. 6, no. 1, p. 56-60
Publication date2019
Abstract

The measurement of chirality and its temporal evolution are crucial for the understanding of a large range of biological functions and chemical reactions. Steady-state circular dichroism (CD) is a standard analytical tool for measuring chirality in chemistry and biology. Nevertheless, its push into the ultrafast time domain and in the deep-ultraviolet has remained a challenge, with only some isolated reports of subnanosecond CD. Here, we present a broadband time-resolved CD spectrometer in the deep ultraviolet (UV) spectral range with femtosecond time resolution. The setup employs a photoelastic modulator to achieve shot-to-shot polarization switching of a 20 kHz pulse train of broadband femtosecond deep-UV pulses (250–370 nm). The resulting sequence of alternating left- and right-circularly polarized probe pulses is employed in a pump-probe scheme with shot-to-shot dispersive detection and thus allows for the acquisition of broadband CD spectra of ground- and excited-state species. Through polarization scrambling of the probe pulses prior to detection, artifact-free static and transient CD spectra of enantiopure [Ru(bpy)3]2+ are successfully recorded with a sensitivity of <2×10−5 OD (≈0.7  mdeg). Due to its broadband deep-UV detection with unprecedented sensitivity, the measurement of ultrafast chirality changes in biological systems with amino-acid residues and peptides and of DNA oligomers is now feasible.

Research groups
Citation (ISO format)
OPPERMANN, Malte et al. Ultrafast broadband circular dichroism in the deep ultraviolet. In: Optica, 2019, vol. 6, n° 1, p. 56–60. doi: 10.1364/OPTICA.6.000056
Main files (1)
Article (Published version)
Identifiers
Journal ISSN2334-2536
542views
518downloads

Technical informations

Creation09/01/2019 10:43:00
First validation09/01/2019 10:43:00
Update time15/03/2023 15:21:30
Status update15/03/2023 15:21:29
Last indexation31/10/2024 12:24:31
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack